raindancewx

Blizzard warnings for California for up to six feet of snow by Friday, and 100 mph winds. Fingers crossed.

I look at Flagstaff as a proxy for Arizona, and they'll switch to positive anomalies for snow for winter to date by the end of January. The Upper Rio Grande basin in Colorado is now above average, and the north-central mountains in NM are nearing average as of data through yesterday. So the snow pack feeding the Rio Grande is actually in decent shape. Even if the Southwest has large areas that finish wet in January in a La Nina, a dry Spring is still favored. But my research suggests a less dry Spring is possible if large areas of the Southwest pull out a wet January in a La Nina. The pattern is dry overall for the New Mexico valleys, but Albuquerque hasn't hit 60 in like eight-weeks, so it's not like any of the snow on the mountains has melted much. https://www.wcc.nrcs.usda.gov/ftpref/data/water/wcs/gis/maps/co_swepctnormal_update.pdf

The airport got about an inch of snow by midnight 1/25, and it was still snowing until about 1 am. Probably just over an inch fell there, with 0.9" reported for 1/25. I noted way back in October that all ten years to see measurable October snow in Albuquerque had snow in five different calendar months. We're at three now: Oct, Dec, Jan. To keep that tendency alive, we need snow in two of the next four: Feb, Mar, Apr, May. Recent Marches have not had snow, and snow in May is very rare. But I lean toward Feb & Mar, since every prior October snow in Albuquerque has been followed by a March snow.

Meanwhile, in the cold, wet Southwest. Whoops dry warm I mean. It's a La Nina after all. Models still show up to 11 inches of liquid equivalent falling as snow in the mountains of California the next six days.

Nino 4 dropped below 27.0C this week. Except for one week in January 2012, this is the first time for that since the 2010-11 event. We'll see if it continues to trend colder. This event is still similar to 2011-12. However, the 26.9C was the coldest reading in Nino 4 of 2011-12. We're still fairly close to 2007-08 in Nino 4, and that event kept Nino 4 dropping erratically into February. If that happens, we'll drift away from 2011-12 as a good match. Nino1+2 Nino3 Nino34 Nino4 Week SST SSTA SST SSTA SST SSTA SST SSTA 16DEC2020 22.0-0.8 24.3-0.8 25.6-0.9 27.8-0.7 23DEC2020 22.1-1.1 24.5-0.7 25.7-0.9 27.6-0.8 30DEC2020 22.2-1.3 24.4-0.9 25.4-1.2 27.3-1.1 06JAN2021 23.1-0.8 24.7-0.8 25.5-1.1 27.1-1.2 13JAN2021 24.0-0.3 24.7-0.9 25.4-1.2 27.0-1.3 20JAN2021 23.9-0.8 25.2-0.6 25.5-1.1 26.9-1.4 14DEC2011 21.5-1.2 24.1-1.0 25.6-1.0 27.4-1.1 21DEC2011 22.1-1.0 24.5-0.7 25.6-1.0 27.2-1.3 28DEC2011 22.6-0.9 24.4-0.9 25.5-1.1 27.1-1.3 04JAN2012 22.7-1.1 24.6-0.8 25.5-1.0 27.2-1.2 11JAN2012 23.7-0.5 24.8-0.7 25.6-1.0 27.1-1.2 18JAN2012 24.0-0.6 24.9-0.8 25.4-1.2 27.1-1.2 25JAN2012 24.6-0.4 25.2-0.7 25.5-1.2 26.9-1.3

One thing I try to match on is MJO timing. So we'll probably be in MJO phase 7 on 2/1. Some cold ENSO years with high-magnitude phase 7 on 2/1 (1/30-2/3 is my threshold for timing): February 2018, 2012, 2006, 1993, 1990, 1989. If you ignore the early February timing requirement 1999, 2001, 2008, 2017 had amplitude phase 7 too. A lot of El Nino years do too. I did some research the other day: If you get a wet January in a La Nina in the Southwest (seems likely now for at least large portions of Western NM, Arizona, and parts of Utah, and Colorado, Nevada, and California), it does seem like the SW Spring dry signal weakens a bit, but remains. My guess is the weak systems we've been getting all winter won't make it through in the Spring, and it will just be a handful of very powerful upper level lows, probably cold cut off lows that occasionally tap Gulf of California moisture, that bring precipitation. That's probably pretty tornadic if the north is cold and the south is warm, with all the dry and wet air mixing, and it does make me think maybe the WPO will hold on a bit longer than forecast. The right images are what I call the "wet Southwest La Nina" January composite. The left images are the "mixed Southwest La Nina" January composite - where some places are wet and others very dry. The right image seems a lot closer if California gets as much rain and snow as they are forecast to by Friday.

Increasingly looks like California's rain/snow deficits are going to be nearly destroyed or destroyed in the coming days with up to 100 inches of snow forecast in the mountains through Friday Night. A lot of Arizona is going to flip to positive precipitation departures for January after today and Monday. New Mexico already had some areas running above average this month, and the above average moisture should expand here as well.

CFS may radically change by the end of the month, but for now it is on board with the February 2011/2012 blend.

The storm I'm watching the closest is actually the 1/30 (ish) system for NM/CO. That's the only one in the train of systems supported by the SOI crash. It's been trending up in strength on each run of the European. Currently looks like a powerful Pacific cold front for Western NM, but I think it may keep trending up. Euro has up to 100 inches of snow for California over the next six days.

It's the GFS. It's also 15 days out. But still....150+ inches of snow for the mountains of California is currently shown. A lot of it is in the next few days too.

We'll see how it goes. When I looked at the years that had a similar setup to what we see now at the surface, the tendency is for Nino 4 to remain cold pretty deep into the year, even as the other zones warm. Nino 4 getting reinforced by cold waters below the surface moving west and toward the surface is supportive of that. The best subsurface matches for Nov-Jan are probably going to be 1995-96, 2007-08, 2011-12 as a blend, barring a huge last second change late January. That's a pretty typical La Nina look nationally for February.

The MJO on the long-range European update yesterday was forecast to stay in phase 7 from now until 2/20 or so The shorter range models have it in phase 7 through at least week one of February. Good for us in the West for snowpack. Pretty decent warm signal for the East too.

Despite the reputation of La Nina, it does seem like West Texas and north Texas often do fairly well for snow early on in La Ninas. There were some pretty impressive snow events in 2017-18, 2008-09, and 2005-06 really far into the South just off the top of my head. I think Houston, Austin, Brownsville, San Antonio and New Orleans have all had snow in recent La Ninas. Not each city in each year, but you get brief windows.

Today is the 60th day in a row without hitting 60 degrees in Albuquerque. Hasn't actually topped 57 in that time frame either. Places that have hit 60: Boston, New York, Philadelphia, Denver, Billings.

CPC has Texas strongly favored to be warm in the long-range after all the rain and snow forecast for the Southwest. I wasn't expecting the Dakotas to see record warm highs in winter, but I did expect Texas to have warm highs.

I really can't remember the last time I've seen a model forecast this much precipitation for Arizona within ~4 days in real time. Most of this is by day break Tuesday.

Most of the moisture for Western New Mexico, Southwest Colorado, Utah, Arizona and Southern California is within four days now. I'd like to think the European has some handle on it by now. For Arizona, this might be the most significant moisture they've seen in a year or more in some spots.

This is what I was looking for when I made the January 2017 comparison. I don't know it if it will verify. But it's possible now, and this would have been hard to imagine a few weeks ago.

We seem to be going into a diet-cola version of January 2017 with all the moisture set to dump into the West. That's assuming the models are right about the moisture. The purples and yellows are multiple inches of liquid equivalent.

Droughts end. Keep your fingers crossed.

I never really answered what you asked above. Our cold in the West is just inversions and moisture less lows with cold center passing through. I've had like six closed lows pass over me since mid-December and it still hasn't rained officially, or snowed officially at the airport here, even as a lot of the state has seen decent moisture overall. Some places seem to have legitimately picked up 0.5" or more with the storm today and yesterday. Early on, December was a terrible match to 2007. But after 12/10 or 12/15 the pattern became similar. You can see a lot of the US is within one color in 2020-21 v. 2007-08, i.e. within two degrees. I had other analogs to warm up the Northeast & West from 2007-08, so we've actually been moving toward my blend. January 2008 is actually very cold late in the South, and it doesn't look too cold this year, so that will move my blend closer to observations since I've been running too warm in the South so far..

Compared to 1951-2010 averages, my guess is January finishes something like this in the four zones: Nino 4: -1.1C Nino 3.4: -0.9C Nino 3: -0.7C Nino 1.2: -0.5C If my assessment is correct, the structure for the La Nina in January is much closer to a lot of the older La Ninas than the recent events. None of the six closest matches to January are in the past 20 years. A blend of January 2012 and 2011 is somewhat close and looks somewhat similar to the blend but colder in the West. Jan Nino 4 Nino34 Nino3 Nino 12 2012 27.30 25.67 25.09 24.38 2011 26.92 25.00 24.40 24.08 Blend 27.11 25.34 24.75 24.23 2021E 27.00 25.55 24.80 23.80

Decent storm today. Still snowing in the northern areas. More possible by the end of the month. Models are kind of going crazy with precipitation by the end of the month in Arizona. Droughts do end - but it will be interesting to see how much or how little we actually see. GFS is left, Euro is right. Will check back later and see if this has any validity. Arizona has had virtually no rain or snow this January. Las Vegas, NM Red River averages 135 inches of snow a year.

There are slightly different impacts for precipitation patterns in ENSO by season long-term. Down here, La Nina is actually a wet signal most places in September. It's then very dry for Oct-May as a signal. La Nina is not really a huge dry signal for Colorado in winter overall. More important early and late. New Mexico does well for precipitation long-term in periods of strong +NAO or strong -NAO, and you guys do better in between. Essentially, Colorado is part of the Northwest in winter, and part of the Southwest in terms of Fall/Spring for storm patterns. That's how I think of it.

The 1931-32 winter was a cold ENSO winter that followed two El Ninos - fairly rare in the last 90 years. So I did look at it when I did my forecast. That year is severely cold in the West though, and so it hasn't been a great match for the US overall. The distribution of cold highs (<=55F) where I am is uncannily similar to 1936-37, I'm curious to see if that continues. I'll put out a Spring Outlook at some point in the next three weeks, but I am struggling with March at the moment. March 1965 and March 2012 are both very good matches to what I think the La Nina will look like in Spring, but one is incredibly cold in March, and one is incredibly hot. The other similar years are in between.